1. Field of the Invention
The present invention relates to an improved cleaning roller suitable for use in a cleaner applying device for bowling lane maintenance machines, floor cleaning machines and the like.
2. Description of the Prior Art
To play the bowling game as a sport in a proper manner, it is required that the bowling lanes always be in their best condition. For such a purpose, the top faces of the bowling lanes must always be cleaned and conditioned by an oil treatment to have a very thin film of conditioning oil.
To this end, the applicant had proposed "a cleaning mechanism for bowling lane maintenance machines" as set forth in Japanese Utility Model Application No. 60-50769/1985. A similar cleaning mechanism is disclosed in U.S. Pat. No. 3,604,037.
Such cleaning mechanisms comprise a cleaning roller for cleaning and conditioning the top face of a bowling lane before applying oil thereto, an oil applying roller and a buffing roller.
These rollers are separately driven from respective drive motors. The cleaning roller is brought into contact with the top face of the bowling lane under a relatively low pressure while the buffing roller must contact the top face of the bowling lane under a relatively high pressure.
In the past, almost all the rollers were in the form of a straight roller which has its invariable diameter between the opposite ends of the roller. If such a straight roller is urged onto a flat surface with a very high pressure at the opposite ends of the roller, the latter is insufficiently engaged by the top face of a bowling lane particularly at the central portion of the roller along the length thereof. This results in buffing, cleaning and other operations which are not uniform in the width direction of the bowling lane.
Usually, the outer periphery of such rollers is covered with a cloth and/or a resilient material such that the outer roller periphery can self-adjust to some degree relative to irregularities of the top lane face, curvature of the roller and irregular pressures. If a pressing roller having a reduced diameter is used, however, it is difficult to increase the rigidity of the entire roller and also to produce the roller more simply and inexpensively.
More particularly, a prior art cleaning roller of such a construction as shown in FIG. 2 is rotatably driven to wipe off a film of oil while applying the oil to floor face of a bowling lane. The cleaning roller 1 comprises a core 2 in the form of a straight bar and a resilient body 3 mounted about the core. The resilient body 3 has ends each of which is spaced inwardly from the corresponding end of the core 2. The intermediate portion of the resilient body 3 between the opposite ends thereof has an invariable external diameter over the length of the resilient body 3. When a large force shown by F in FIG. 3 is simultaneously exerted on each of the opposite ends of the core 2, the roller core 2 is curved upwardly as shown in FIG. 2. In such a case, the contact pressure will be reduced at the central portion of the roller 1 rather than the opposite ends thereof, resulting in non-uniform contact.